Field of the Invention
The present invention relates to a tilting oxygen converter provided with a suspension system for the converter container, said system connecting said container to a support ring.
State of the Art
The main object of an oxygen converter is to convert the cast iron produced in the blast furnace into raw liquid steel, which can be then refined in the secondary steel production department.
The principal functions of the oxygen converter, also known as a B.O.F. (Basic Oxygen Furnace), are to decarbonize and remove the phosphorus from the cast iron and optimize the temperature of the steel so that further treatments can be carried out before casting with minimum heating and cooling of the steel.
The exothermic oxidation reactions which are generated in the converter produce a lot of thermal energy, more than the energy needed for reaching the determined temperature of the steel. This extra heat is used to melt the scrap metal and/or the added ferrous mineral. As the B.O.F. substantially is a furnace, it is also subject to thermal dilatations.
As example of as oxygen converter, belonging to the state of the art, is described in the document U.S. Pat. No. 5,364,079.
Said converter consists of a container, defining the reactor and having a substantially cylindrical shape, supported by a support ring (“trunnion ring”), surrounding the container and suitably spaced therefrom, provided with two diametrically opposed supporting pins (“trunnions”), the assembly supported by two supports anchored to the ground. The container relation control is keyed onto one of the two supporting pins.
Said converter is supported by means of an external support ring and a suspension consisting of a plurality of articulated braces and related supports, arranged on the lower side of the support ring when the converter is in a vertical position. Each support, articulated by means of ball joints, is designed to be fixed to the support ring on one side and to the container on the other side.
Thereby, the converter is supported by a series of articulated supports which allow the container dilatations and self-alignment between the external support ring and said container.
Although the described system allows self-alignment between the two units, the presence of numerous ball joints disadvantageously determines considerable maintenance of the latter over time, constant greasing and preventive replacement of the joints given the heavy operating conditions to which they are subjected.
Centring the container and the support ring is also important in order to conveniently allow the thermal deformations or expansions of the container due to the high temperatures reached during the conversion process.
The need is therefore felt to provide an oxygen converter which allows the aforementioned drawbacks to be overcome.